99 Si needs new head due to thermal erosion... new to swapping... do i have a choice in what head i can even put in or is the stock head the only choice ?? any info will be greatly appreciated.

 

you can use another b16a2 head which is a pr3 head, good head. If you want more, you can use a complete integra type r head. Also a pr3 head. A gsr head would also work and raise your compression I hear, but I'm sure not enough to make a bit of difference